


His little brother

by river_chan



Category: Ensemble Stars! (Video Game)
Genre: Age Regression/De-Aging, Brotherly Love, Gen, Hiiro and Rinne are a happy family okay, Hiiro lives with Rinne and Niki I guess, Hugs them, If you sexualize this I will melt your fingernails, Just wholesome brother things, Platonic Cuddling, Some implied Rinniki, i guess, sfw age regression
Language: English
Status: Completed
Published: 2021-01-10
Updated: 2021-01-10
Packaged: 2021-03-14 20:22:20
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,227
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28676625
Author URL: https://archiveofourown.org/users/river_chan/pseuds/river_chan
Summary: Rinne brought home an adorable teddy bear and for his younger brother, and Hiiro was absolutely delighted.
Relationships: Amagi Hiiro & Amagi Rinne
Comments: 7
Kudos: 30





	His little brother

**Author's Note:**

> So I started writing this at the time of Rinne feature scout where he like got the teddies for Anzu and she didn't want them so he was like k imma give them to Kohaku-chan then and I was just screaming riNNE YOU LITTLE FUCK YOU LITERALLY HAVE A BABY BROTHER GIVE THE PLUSHIE TO HE?????
> 
> So yeah. I also had this Hiiro age aggression headcanon for a while and I LIVE for wholesome amagi brothers content so I wrote this. Enjoy.
> 
> Unless you think of this as some kind of ship/kink. In which case I will literally melt your fingernails. They just bros trying to cope okay :(

When Rinne came home, Hiiro immediately noticed the bright smile across his face and the bag he was carrying.

"What's the matter, nii-san? Did something nice happen today?"

"Ya bet it did!" Rinne laughed. "It's a little surprise for you!"

"A surprise for me?" echoed his younger brother, while Rinne reached into his bag, "Ah, weren't you out with Anzu-san today? Why did-"

Hiiro stopped and gasped once he saw what Rinne had in his hands: A tiny, light brown teddy bear plush, with red accents on it's arms, legs and ears and a yellow ribbon at its neck. And its face was so adorable!

"Woah! Is that for me?" Hiiro's eyes sparkled, beaming with amazement, in a way that Rinne never really got to see during their childhood.

Smiling, Rinne nodded. "I was real lucky at the claw machines today, so I got a whole bunch of 'em for Anzu-chan but she didn't want 'em all, and neither did Kohaku-chan, so these are aaaall just for ya!"

After he handed the plushie to his brother, he immediately turned back to reach into his bag again.

But Hiiro didn't even pay attention to that, completely transfixed on the bear in his hands. It was... so cute! It needed the perfect name! But what should he call it? Ahhh, he's too excited to think now! He was so focused on the plushie, it didn't seem like he was going to notice Rinne anytime soon, so he whistled to get his attention.

Hiiro instantly looked up and his eyes went even wider. Rinne was holding at least a dozen of plushies in his arms. He was practically hugging them, that was the only way he could carry all of them at ones. They were all different, all kinds of animals, or some were mascots of some kinds of TV shows that Hiiro barely had any time to watch yet. But either way, all of them were incredibly adorable!

"Woah, are... Are all of them for me?"

"Yup!" Rinne snickered, setting the plushies down on the table in front of him, "Hehe, I knew you'd like them."

Hiiro got up and dashed towards his older brother with open arms before hugging him tightly. "Thank you sooo much, nii-chan!"

Rinne had already suspected how Hiiro might react upon receiving all of these plushies, and his tone of voice and the normally untypical nickname gave it away. Smiling, he pat his brother's head as he leaned against his chest. "We're havin" a  little little bro today, huh?"

After a moment of hesitation, Hiiro leaned back to look at Rinne with a concerned look, the sparkle that had just been in his eyes fading. "...if it's okay...?"

Rinne's hand found it's way back into Hiiro's bright red hair, ruffling it rather roughly, but lovingly. "Of course it is!"

He worried that his brother's childish sparkle would completely vanish, but once Rinne said that, he luckily immediately got into the spirit of a child again. He went back to hugging his older brother tightly, laughing like a carefree child. With him, he felt safe. He knows that he can trust him. I knows Rinne will take good care of him.

"I love you, nii-chan!" exclaimed Hiiro as Rinne picked him up to hold him over his shoulders. Sure, lifting an actual child would be easier, but luckily, Rinne was rather strong.

"I love you too, lil bro," he said after giving him a little kiss on his forehead. "Sooo, I bet you're hungry, right, buddy?" asked Rinne, to which Hiiro nodded enthusiastically. He simply couldn't help but smile at Hiiro's happiness. He's only somewhat recently started trying age regression, and in the beginning, it was incredibly hard for him.

Mainly because Hiiro didn't know what to do. Of course, there was nothing  to do . Aside of being a child. But that was so hard for him. Nothing really traumatic per say happened during Hiiro's childhood that caused him to regress, but... Once he came to the city and saw what a childhood is actually supposed to be like...

Playgrounds, toys, TV shows, amusement parks all sorts of fun stuff. Nothing of which were in his hometown when he grew up. And there wasn't much room for just playing around either, when he was raised just to serve his older brother, the future chief.

Before he even left his hometown, he never realized how much it damaged him, not being allowed to be a real child, since he though that was normal, but once he saw children on a playground in the city, he felt like he was missing a huge part of being a human. But trying to unlearn what he has been taught and just let go... It was really hard for Hiiro.

Today though, the moment he saw the teddy, it was like a switch was flipped and he easily slipped into the mindset of a little kid. Rinne could immediately tell how different his brother's presence became in that moment.

And now seeing his little bro that never got to be a real child laughing in his arms, so carefree... Rinne was glad. He didn't get to be the good, caring older brother he wished he was when they were children, so now he was the chance to make up for it. So in a way, this wasn't only therapeutic for Hiiro, but also for Rinne.

Though neither of them know too much about 'typical childhoods', so they basically just looked up what age regressors usually like to do.

So when he was grocery shopping with Niki the other day, and he found these dino shaped nuggets, he knew he just had to buy them. At the cost of like 600 yen, his dignity and a very weird look from Niki.

The reason he judged him wasn't the dino shapes really, it was more the fact that he's buying some cheap ass frozen nuggets when he literally lives with a chef. Sure, he could ask Niki to cook some nice meals for Hiiro, but... Then Niki would be his nii-chan, right? But Rinne is Hiiro's brother, not Niki, not anyone else, so it's Rinne that needs to take care of him.

So he eventually learned how to use an oven. Progress, for sure. Well, to be frank, he was learning from an excellent chef, by now he should know more than putting stuff into an oven, but hey! It's still progress!

"What would ya say about some dino nuggets?" Rinne suggested, nuzzling the little's forehead. Well, it wasn't really a suggestion, as it was like the only option. While he also read that mac and cheese is a very popular food among age regressors, he still can't make that properly despite Niki trying his best to teach him. But if it's just shoving some nuggies into an oven, Rinne can probably do it without burning the house down.

"Dino nuggets?" Hiiro asked, confused, then gasped, "Are those nuggets from dinosaurs?"

It's moments like these where Rinne is seriously questioning whether that's just the kid inside of Hiiro speaking with childish silliness or he actually thought that's what they were made of. Either way, there's no real harm in playing with the younger brother a bit, right? So Rinne nodded, grinning and answered, "Mmh, they're made from real dinos! That's what makes them taste so good! And me cooking them, of course~!"

Hiiro simply laughed at that last comment. "Haha, nii-chan, you’re not uncle Niki!"

That jab at Rinne's incompetence when it comes to cooking didn't hurt anymore once he heard his brother said 'uncle Niki'. Like seriously, how adorable is this? Rinne couldn't help but chuckle. Wait until he tells Niki what Hiiro just called him! How cute!

Although uncle really isn't what he is to him if you actually think about it... He's a brother in law, not an uncle at all... But whatever, who cares about that shit, it's still cute as fuck!

Rinne pulled his brother even closer and ruffled his hair again. "Well, the nuggets take like 10 minutes, what do you wanna do until then?"

"Hmmmmm..." Hiiro took a second to think, and Rinne patiently waited for him. "The plushies!" he eventually shouted, louder than necessary.

"Got it!" Rinne sat Hiiro down on the carpet and put all of his new plushies next to him. But when he was about to leave for the kitchen, there was something on his leg. Looking down, Hiiro was clinging onto his brother's leg.

"...I don't want nii-chan to leave..." he murmured.

Again, Rinne ruffled through Hiiro's red mess of hair, a kind smile on his face. "Oh, buddy, I'm not leaving ya. I just gotta throw the nuggets into the oven, it'll be fast, I promise."

"How fast?" Hiiro wanted to know, pouting.

"Hmm... let's say, 20 seconds?"

A moment of consideration, then Hiiro let go. "I will be counting!" he announced with a serious voice. Well, as serious as a little child can be.

Once Rinne left, he began counting out loud. "1...2...3...4…5…6…7…8…9…10…" Very quick steps, followed by the sounds of scrambling around, trying to open the pack.

"11…12…13…14…15…16…17…18…19…....20..." Hiiro reached twenty, but his brother still hasn't returned. Instead, other hurried sounds echoed from the kitchen, along with some bad words by Rinne. He really shouldn't be swearing when a little kid can hear him...

Very disappointed and angry, Hiiro continued to count. Until he reached 26, at which point Rinne finally made it back, completely out of breath. "I really overestimated myself, huh..." he murmured to himself.

"Nii-chan, you're late! By," he held up six fingers, "this many seconds!"

Hiiro really can't seem to choose what kind of age he wants to regress to. Using fingers to express numbers but also counting to thirty... His little age is pretty fluid, it's normally somewhere between 4 and 10, which is a pretty huge range. But it's not like Rinne cares. If Hiiro is the happiest this way, that's the important thing, not doing things that would be developmentally appropriate for a kid that age.

Rinne sat down on the floor next to his little brother, "Sorry, bud. It took longer than I thought," but Hiiro's frown still didn't disappear. Until his eyes suddenly lit up and a tiny grin showed up on his face. It was devilish, but still containing a child's innocence.

"That means: Tickle attack!" he exclaimed as he jumped onto his brother before he could react, pushing him onto the sofa behind them. While trying to pin down Rinne's arms, Hiiro had his hands all over him, tickling him in quick motions.

Now, Rinne isn't ticklish. Not in the slightest. Though during childhood, Hiiro would have never even thought about tickling the future chief, so there's no way he could know.

But Rinne didn't keep a straight face during this, no, he played along. He jerked back and forth, laughing and screeching seemingly uncontrollably. He pretended like he was ticklish and absolutely at Hiiro's mercy, as he weakly tried to push the little's hand away. Just to keep Hiiro happy.

"Ah! Hii-! Hiiro! You, nnghaaaaha!" he got out in between giggling and screaming. Hiiro was laughing, too. Just carelessly playing around with his older brother like that... This is what his childhood should have been like. He enjoyed being in control, having Rinne at his mercy, or at least he thought so. His act of actually being ticklish was incredibly believable. Probably from all the times he's tortured Niki like that before.

Eventually, Hiiro stopped, and watched Rinne trying to regain his composure with a satisfied smile. Then, he let himself fall onto Rinne, resting on his chest as he hugged him. His heartbeat was surprisingly calm, considering what his nii-chan just went through, Hiiro thought.

"I love you, nii-chan..." the little mumbled against his brother's chest.

"I love ya ten time more~" Rinne pressed a little kiss against Hiiro's forehead and wrapped his arms around him. It didn't seem like the younger boy was going to move anytime soon, so Rinne adjusted their position to be more comfortable, so that they rested on the sofa's soft pillows.

"Nooo, I love you wayyyy more than that!"

"Surely you don't. Because I love you a whole lot!" said Rinne, and he expected this to go back and forth, but surprisingly, Hiiro stayed quiet. "Hiiro?"

"Nii-chan... Your heartbeat is nice..." With his ear pressed against his older brother's chest, he could easily hear his heart inside.

Rinne tilted his head. "Huh? Ya think so?"

The head on his chest nodded slightly, but that was all the response he got.

The steady thumping of Rinne's heart was incredibly calming. It was such a pretty rhythm. It felt like home. He was home. Along with the nice sensation of being hugged, it didn't take long until Hiiro drifted off into a nice little nap.

And well, due to Rinne being in a hurry when he put the nuggets in the oven, he actually forgot to set a timer. And by now, he's totally forgotten about the nuggets entirely. But it's okay. As long as Hiiro is happy. Niki would come home soon anyway and make dinner for the three of them.

**Author's Note:**

> Honestly dino nuggets are my SHIT.


End file.
